Chelsea Clinton Partied Until 5 a.m. on Wedding Day!

No wonder Chelsea Clinton and Marc Mezvinsky danced like pros at their wedding.

The new issue of Us Weekly reports that Dancing With the Stars pro Maksim Chmerkovskiy choreographed their first twirl to "Feeling Good." A source says he also gave the couple -- who said "I Do" in front of 500 guests in upstate New York last Saturday -- pre-wedding dance lessons.

The previous night, Chelsea and Mezvinsky's mutual pal Tim Blane wowed guests when he performed with his band at their rehearsal dinner.

"We were so honored that they asked us to play a role in their special weekend," Blane tells Us. "Chelsea and I have been close friends since we were teenagers and I could not be happier for her and her new husband."

After the wedding ceremony, Chelsea changed into another Vera Wang gown for the reception and afterparty, which went until 5 a.m., when Mezvinsky, 32, made quite an exit with his new wife.